The Magento extension caps the max record size to 10kb by default.
If your Algolia plan includes a higher max record size allowance, you can increase this value in the extension.
For extension version 3.9.1 and later you can do that in the Admin panel of your Magento project, go to Stores > Algolia Search > Credentials and Basic Setup > Advanced to open the configuration page for Algolia.
Enter the value for Max record size limit per record as per your requirement.
Click Save Config at the top right to save your configuration.
For extension version 3.9.0 and below, you can follow this guide https://support.algolia.com/hc/en-us/articles/4406477979025.